package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    private ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    public void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable{
        @Override
        public void run() {
            while (true){
                try {
                    //1.获取队列中的订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    //2.创建订单
                    proxy.createVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                }
            }
        }
    }

    private IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString()
        );
        //2.判断结果是否为0
        int r=result.intValue();
        if(r != 0){
            //2.1不为0，没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //2.2为0，有购买资格，把下单信息保存到阻塞队列
        VoucherOrder voucherOrder = new VoucherOrder();
        //2.3. 订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //2.4. 用户id
        voucherOrder.setUserId(userId);
        //2.5. 代金券id
        voucherOrder.setVoucherId(voucherId);
        //2.6放入阻塞队列
        orderTasks.add(voucherOrder);
        //3.获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //4.返回订单id
        return Result.ok(orderId);
    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1. 查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //2. 判断秒杀是否开始
//        if(voucher.getBeginTime().isAfter(LocalDateTime.now())){
//            return Result.fail("秒杀尚未开始");
//        }
//        //3. 判断秒杀是否已经结束
//        if(voucher.getEndTime().isBefore(LocalDateTime.now())){
//            return Result.fail("秒杀已经结束");
//        }
//        //4. 判断库存是否充足
//        if(voucher.getStock()<1){
//            return Result.fail("库存不足");
//        }
//        Long userId = UserHolder.getUser().getId();
//        //创建锁对象
//        SimpleRedisLock lock = new SimpleRedisLock(stringRedisTemplate, "order:" + userId);
//        //获取锁
//        boolean isLock = lock.tryLock(1000);
//        if(!isLock){
//            return Result.fail("不允许重复下单");
//        }
//        try {
//            //获取代理对象（事务）
//            IVoucherOrderService proxy =(IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } finally {
//            lock.unlock();
//        }
//
//    }


    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //5.一人一单
        Long userId = voucherOrder.getUserId();
        //5.1查询订单
        int count= query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //5.2判断是否存在
        if(count>0){
            log.error("用户已经购买过一次了");
            return;
        }
        //6. 扣减库存
        seckillVoucherService.update()
                .setSql("stock=stock-1")
                .eq("voucher_id", voucherOrder.getVoucherId())
                .gt("stock",0)
                .update();
        //7. 创建订单
        save(voucherOrder);
    }
//    @Transactional
//    public Result createVoucherOrder(VoucherOrder voucherOrder) {
//        //5.一人一单
//        Long userId = UserHolder.getUser().getId();
//        //5.1查询订单
//        int count= query().eq("user_id", userId).eq("voucher_id", voucherOrder).count();
//        //5.2判断是否存在
//        if(count>0){
//            return Result.fail("您已经购买过一次了");
//        }
//        //6. 扣减库存
//        seckillVoucherService.update()
//                .setSql("stock=stock-1")
//                .eq("voucher_id", voucherOrder)
//                .gt("stock",0)
//                .update();
//        //7. 创建订单
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //7.1. 订单id
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        //7.2. 用户id
//        voucherOrder.setUserId(userId);
//        //7.3. 代金券id
//        voucherOrder.setVoucherId(voucherOrder);
//        save(voucherOrder);
//        //8. 返回订单ID
//        return Result.ok(orderId);
//    }
}
